cpython/Lib/test/test_range.py

147 lines
5.4 KiB
Python

# Python test set -- built-in functions
import test.support, unittest
import sys
import pickle
import itertools
import warnings
warnings.filterwarnings("ignore", "integer argument expected",
DeprecationWarning, "unittest")
# pure Python implementations (3 args only), for comparison
def pyrange(start, stop, step):
if (start - stop) // step < 0:
# replace stop with next element in the sequence of integers
# that are congruent to start modulo step.
stop += (start - stop) % step
while start != stop:
yield start
start += step
def pyrange_reversed(start, stop, step):
stop += (start - stop) % step
return pyrange(stop - step, start - step, -step)
class RangeTest(unittest.TestCase):
def assert_iterators_equal(self, xs, ys, test_id, limit=None):
# check that an iterator xs matches the expected results ys,
# up to a given limit.
if limit is not None:
xs = itertools.islice(xs, limit)
ys = itertools.islice(ys, limit)
sentinel = object()
pairs = itertools.zip_longest(xs, ys, fillvalue=sentinel)
for i, (x, y) in enumerate(pairs):
if x == y:
continue
elif x == sentinel:
self.fail('{}: iterator ended unexpectedly '
'at position {}; expected {}'.format(test_id, i, y))
elif y == sentinel:
self.fail('{}: unexpected excess element {} at '
'position {}'.format(test_id, x, i))
else:
self.fail('{}: wrong element at position {};'
'expected {}, got {}'.format(test_id, i, y, x))
def test_range(self):
self.assertEqual(list(range(3)), [0, 1, 2])
self.assertEqual(list(range(1, 5)), [1, 2, 3, 4])
self.assertEqual(list(range(0)), [])
self.assertEqual(list(range(-3)), [])
self.assertEqual(list(range(1, 10, 3)), [1, 4, 7])
self.assertEqual(list(range(5, -5, -3)), [5, 2, -1, -4])
a = 10
b = 100
c = 50
self.assertEqual(list(range(a, a+2)), [a, a+1])
self.assertEqual(list(range(a+2, a, -1)), [a+2, a+1])
self.assertEqual(list(range(a+4, a, -2)), [a+4, a+2])
seq = list(range(a, b, c))
self.assertTrue(a in seq)
self.assertTrue(b not in seq)
self.assertEqual(len(seq), 2)
seq = list(range(b, a, -c))
self.assertTrue(b in seq)
self.assertTrue(a not in seq)
self.assertEqual(len(seq), 2)
seq = list(range(-a, -b, -c))
self.assertTrue(-a in seq)
self.assertTrue(-b not in seq)
self.assertEqual(len(seq), 2)
self.assertRaises(TypeError, range)
self.assertRaises(TypeError, range, 1, 2, 3, 4)
self.assertRaises(ValueError, range, 1, 2, 0)
self.assertRaises(TypeError, range, 0.0, 2, 1)
self.assertRaises(TypeError, range, 1, 2.0, 1)
self.assertRaises(TypeError, range, 1, 2, 1.0)
self.assertRaises(TypeError, range, 1e100, 1e101, 1e101)
self.assertRaises(TypeError, range, 0, "spam")
self.assertRaises(TypeError, range, 0, 42, "spam")
self.assertEqual(len(range(0, sys.maxsize, sys.maxsize-1)), 2)
r = range(-sys.maxsize, sys.maxsize, 2)
self.assertEqual(len(r), sys.maxsize)
def test_repr(self):
self.assertEqual(repr(range(1)), 'range(0, 1)')
self.assertEqual(repr(range(1, 2)), 'range(1, 2)')
self.assertEqual(repr(range(1, 2, 3)), 'range(1, 2, 3)')
def test_pickling(self):
testcases = [(13,), (0, 11), (-22, 10), (20, 3, -1),
(13, 21, 3), (-2, 2, 2)]
for proto in range(pickle.HIGHEST_PROTOCOL + 1):
for t in testcases:
r = range(*t)
self.assertEquals(list(pickle.loads(pickle.dumps(r, proto))),
list(r))
def test_odd_bug(self):
# This used to raise a "SystemError: NULL result without error"
# because the range validation step was eating the exception
# before NULL was returned.
with self.assertRaises(TypeError):
range([], 1, -1)
def test_range_iterators(self):
# exercise 'fast' iterators, that use a rangeiterobject internally.
# see issue 7298
limits = [base + jiggle
for M in (2**32, 2**64)
for base in (-M, -M//2, 0, M//2, M)
for jiggle in (-2, -1, 0, 1, 2)]
test_ranges = [(start, end, step)
for start in limits
for end in limits
for step in (-2**63, -2**31, -2, -1, 1, 2)]
for start, end, step in test_ranges:
iter1 = range(start, end, step)
iter2 = pyrange(start, end, step)
test_id = "range({}, {}, {})".format(start, end, step)
# check first 100 entries
self.assert_iterators_equal(iter1, iter2, test_id, limit=100)
iter1 = reversed(range(start, end, step))
iter2 = pyrange_reversed(start, end, step)
test_id = "reversed(range({}, {}, {}))".format(start, end, step)
self.assert_iterators_equal(iter1, iter2, test_id, limit=100)
def test_main():
test.support.run_unittest(RangeTest)
if __name__ == "__main__":
test_main()